Kinetic Studies on the Synthesis of Monoclinic Li3V2(PO4)3 via Solid-State Reaction.

The data obtained by thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (XRD) measurements of the stoichiometric mixture of LiNO3, NH4VO3, and NH4H2PO4 were analyzed by both the Flynn-Wall-Ozawa (FWO) and Friedman-Reich-Levi (FRL) methods. The whole solid state reaction process could be divided into four stages corresponding to α values of 0.03-0.20, 0.30-0.60, 0.70-0.80, and 0.90-0.99. The nucleation of LiVP2O7 (α = 0.70-0.80) is a determining step of the four-reaction processes, for which the mechanism of random nucleation and subsequent growth, described by the Avrami-Erofeev equation (n = 4) G(α) = [-ln(1 - α)]4, was assumed. Moreover, the Gibbs free energy of activation ΔG*, enthalpy of activation ΔH*, and entropy of activation ΔS* at maximum temperature of the peak for the determining step were 99.24 kJ·mol-1, 199.97 kJ·mol-1, and 136.30 J·mol-1·K-1, respectively. Finally, XRD analyses confirmed that the Li3V2(PO4)3 synthesized by the precursor route is a pure phase.

Interleukin-28B genetic variations and spontaneous clearance of hepatitis C antibody-positive blood donors in China.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) near the interleukin (IL)28B gene have been shown to be associated with spontaneous clearance of hepatitis C virus (HCV) infection in western populations. Anti-HCV-reactive and HCV RNA-negative samples were often found in Chinese blood donors. This study was to determine whether the IL28B gene variant is also associated with the natural outcome of HCV infection in Chinese blood donors. STUDY DESIGN AND METHODS: A total of 111 anti-HCV-negative blood donors and 100 anti-HCV-reactive subjects were enrolled in this study. HCV-infected blood donors were classified into spontaneous clearance group and chronic infection group through HCV RNA detection. IL28B genetic variations (rs8099917 and rs12979860) were genotyped by polymerase chain reaction and direct sequencing. RESULTS: A total of 24 (24.0%) donors spontaneously cleared HCV. The rs12979860 C allele frequency was 90.3% and the rs8099917 T allele frequency was 96.7% in our study. The rs12979860 CC genotype was strongly associated with spontaneous HCV clearance. Female blood donors had a higher rate of spontaneous HCV clearance than male donors (15/42 [35.7%] vs. 9/58 [15.5%], p = 0.02). CONCLUSIONS: The rs12979860 CC variant upstream of IL28B gene is associated with spontaneous clearance of HCV in Chinese blood donors and female donors are more likely to clear HCV infection than male donors.

Molecular dynamics simulations of adsorption behavior of DDAH, NaOL and mixed DDAH/NaOL surfactants on muscovite (001) surface in aqueous solution.

The adsorption mechanism of collectors on minerals is of fundamental importance in the research and development of flotation science and processing technology. To examine the effect of cationic dodecylamine hydrochloride (DDAH), anionic sodium oleate (NaOL) and mixed DDAH/NaOL surfactants with different molar ratios on the adsorption behavior on the muscovite (001) surface, the adsorption mechanism of DDAH, NaOL and their mixture on the muscovite (001) surface in neutral aqueous solution was investigated by molecular dynamics (MD) simulations. The results showed that the cationic DDAH molecules absorb on the muscovite (001) surface by electrostatic interactions and hydrogen bonding, whereas the anionic NaOL molecules cannot independently adsorb on the muscovite surface. Based on the analysis of the density distribution profile, radial distribution function (RDF) and interaction energy between surfactant molecules and muscovite surface, and the root mean square displacement (RMSD) of surfactants on water-muscovite interface, individual DDAH surfactant is a superior collector for the muscovite flotation. The molar ratio of DDAH/NaOL surfactants is found to be a key factor in the flotation response of muscovite. No significant adsorption of 1:2, 1:3 and 1:4 mixed DDAH/NaOL surfactants on the muscovite surface can be detected, while an effective adsorption was observed for the DDAH/NaOL mixture in molar ratios of 1:1, 2:1, 3:1 and 4:1. The cationic DDAH surfactant was determined to play a primary role in the adsorption of the mixed surfactants on the muscovite surface, while the anionic NaOL molecules co-adsorb with the DDAH molecules. The additional micro-flotation experiments under neutral aqueous conditions also showed that the flotation recovery of muscovite was the highest in the presence of DDAH surfactant, which was consistent with the findings derived from MD simulations.

Molecular Dynamics Simulation Study on the Interactions of Mixed Cationic/Anionic Collectors on Muscovite (001) Surface in Aqueous Solution.

In this study, the adsorption mechanisms of dodecylamine hydrochloride(DDAHC), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate(SDBS), and their mixed anionic/cationic collectors at ten different molar ratios on a muscovite (Mcv) surface in neutral aqueous solution were assessed by molecular dynamics simulations (MDS). According to the snapshot, interaction energy, radial distribution function (RDF), and density profile between the Mcv surface and collector molecules, the individual DDAHC collector was an effective collector for the flotation of Mcv. The molar ratio of anionic/cationic collectors was determined to be an essential factor in the flotation recovery of Mcv. The DDAHC collector was involved in the adsorption of the mixed anionic/cationic collectors on the Mcv (001) surface, whereas SDS and SDBS collectors were co-adsorbed with DDAHC. The mixed cationic/anionic collector showed the best adsorption on the Mcv surface in a molar ratio of 2. Additionally, SDBS, which has one more benzene ring than SDS, was more likely to form spherical micelles with DDAHC, thus resulting in better adsorption on the Mcv surface. The results of micro-flotation experiments indicated that the DDAHC collector could improve the flotation recovery of Mcv in neutral aqueous solution, which was in agreement with MDS-derived findings. In conclusion, DDAHC alone is the optimum collector for Mcv flotation under the neutral aqueous conditions, while the mixture of DDAHC and SDBS collectors (molar ratio = 2:1) exhibits the similar flotation performance.

Experiences of interpersonal interaction among patients with chronic schizophrenia: A phenomenological study.

PURPOSE: To explore the subjective interpersonal interaction experiences of patients with chronic schizophrenia. DESIGN AND METHODS: Descriptive phenomenological, purposive sampling, in-depth one-to-one, and unstructured interviews were used. Colaizzi's method was used to analyze narratives. FINDINGS: Three themes and six subthemes were emerged: Feelings associated with interpersonal interactions (pleasant and unpleasant feelings experienced during interpersonal interactions); interpersonal interaction is a dynamic process (Positive and negative dynamic processes); selection of interaction targets (limitations in the selection of interaction targets and selection criteria for interaction targets). PRACTICE IMPLICATIONS: Professionals should understand the interpersonal interactions experiences of patients with schizophrenia to help them have a better interpersonal relationship.

Effects of Boric Acid Ester Modified Magnesium Borate Whisker on the Mechanical Properties and Crystallization Kinetics of Polypropylene Composites.

Polypropylene (PP) is notch sensitive and brittle under severe conditions of deformation, limiting wider range of its usage as a structural load-bearing polymer. Hence, in this work the magnesium borate whisker (MBw), with similar mechanical properties to carbon fiber but much less expensive than polycrystalline silicon carbide, was modified by boric acid ester (BAE) and then used to fabricate PP composites. The mechanical properties, morphology, and non-isothermal crystallization property of virgin PP, PP/MBw, and PP/BAE-MBw composites were studied through mechanical testing, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC), respectively. The non-isothermal crystallization data was analyzed via Mo, Kissinger, and Dobreva methods. The results reveal that the incorporation of BAE-MBw into PP matrix results in higher tensile strength and impact strength than those of virgin PP and PP/MBw composite. The activation energies based on Kissinger were 190.20 kJ/mol for virgin PP, 206.59 kJ/mol for PP/MBw, and 218.98 kJ/mol for PP/BAE-MBw. The nucleation activities of whiskers determined by the Dobreva model were 0.86 for PP/MBw and 0.75 for PP/BAE-MBw. As a result, the whiskers, especially the modified whiskers, act as active substrates to facilitate heterogeneous nucleation, which leads to an increase in crystallization rate.

Effects of Ag0-modification and Fe3+-doping on the structural, optical and photocatalytic properties of TiO2.

Pure TiO2, Ag0-modified TiO2, Fe3+-doped TiO2, and Ag0-modified/Fe3+-doped TiO2 photocatalysts were synthesized via sol-gel technology. The crystal structure, element composition and surface morphology of the obtained photocatalysts were characterized via XRD, XPS, SEM and TEM, respectively. The results indicate that Ag-TiO2 samples show higher photocatalytic activity than pure TiO2. Unexpectedly, the photocatalytic activities of Fe-TiO2 and 1% Ag/1% Fe-TiO2 are lower than pure TiO2. To analyze the main factors affecting photocatalytic performance, the samples were further investigated by PL, DRS and BET. The results prove that the additions of Ag and Fe are advantageous for inhibiting the recombination of photoinduced pairs and improving the utilization of light. Fe-TiO2 and 1% Ag/1% Fe-TiO2 exhibit smaller specific surface areas than pure TiO2, which is the primary reason for their reduced photocatalytic performances.